ES2264522T3 - POLYOLEFINIC COMPOSITIONS WITH HIGH TENACITY. - Google Patents

Abstract

A polylefin composition comprising (A) from 15 to 40% by weight of a crystalline propylene copolymer with at least one alpha-olefin of formula H2C = CHR2R1, where R1 is H or a linear or branched alkyl containing at least less than 90% by weight of propylene, and with solubility in xylene at room temperature less than 15% by weight; (B) from 60 to 85% by weight of an elastomeric fraction comprising: (1) a copolymer of propylene with ethylene optionally containing 0.5 to 5% by weight of a diene, containing from 20 to 35% by weight of ethylene and with solubility in xylene at room temperature greater than 70% by weight, the intrinsic viscosity (in tetrahydronaphthalene, at 135 ° C) of the fraction being soluble in xylene exceeding 3.0 dl / g up to 6.0 dl / g ; and (2) an ethylene copolymer with at least one alpha-olefin of formula H2C = CHR2, wherein R2 is a linear or branched C2_8 alkyl, optionally containing 0.5 to 5% by weight of a diene, containing 15% to 40% by weight of alpha-olefin, with solubility in xylene at room temperature greater than 25% by weight, the intrinsic viscosity (in tetrahydronaphthalene, at 135 ° C) of the xylene soluble fraction ranging between 0.5 and 5 , 0 dl / g; oscillating the weight ratio (1) (2) between 1: 5 and 5, 1.

Description

Polyolefin compositions with high tenacity.

The present invention relates to compositions polyolefins that have improved toughness, which retain softness and improved mechanical properties, which can be used advantageously in flat sheet material, such as membranes of single-layer roof for covering flat roofs commercial and industrial, and in other roofing applications. These compositions can be obtained with a process of sequential polymerization.

Traditionally the construction industry You have used construction asphalt or fiber roofing conventional glass as a preferred material in the construction of roofing However, more recently, the materials of membrane roof have displaced conventional materials like a preferred material due to its resistance to cracking in cold, easy installation, and enhanced overall protection with the Time to escape. In addition, membrane systems are easier and installation insurance and therefore more desirable for the contractor as well as for the consumer.

In this field two types of membrane are used: thermoplastic and elastomeric.

Thermoplastic membranes, such as formed from polyvinyl chloride (PVC), polyethylene chlorinated (CPE), polyethylene chlorosulfonate and the like, can heat sealing or welding with solvent to provide reliable seals of greater resistance; however, these membranes They also have serious disadvantages. For example, the material Thermoplastic must be plasticized to provide flexibility necessary for a roof membrane and plasticizers are very expensive and leach out of the membrane over time resulting in loss of flexibility, it becomes brittle and the resistance to cracking decreases due to the cold of the membrane. In addition, the ability of thermoplastic materials to accept Fillers is limited.

In addition, there is a need for a laminate of Alternative PVC, in view of the trend towards an exempt environment of chlorine

Elastomeric membranes, such as EPDM rubbers of ethylene / propylene / diene terpolymers Vulcanized, has gained acceptance quickly, due to the Relevant weather resistance and flexibility. This material it is usually prepared by vulcanizing the composition in the presence of sulfur or sulfur containing compounds.

However, these membranes are easy sealed due to the lack of adhesion of EPDM, especially Cured EPDM, itself, and require an adhesive for bonding the membrane in order to provide a roof covering continues free of leaks. These adhesives add a cost of Significant material and are difficult to apply and time consuming. In addition, adhesives often weaken over time causing delamination of membranes and subsequent leaks in the roof covering. Elastomeric membranes also require an additional expensive curing stage.

In order to avoid the curing process in the state of the art has proposed to use laminar materials to roofing applications comprising an EPDM in combination with highly crystalline thermoplastic promoters, such as high density polyethylene (HDPE), low density polyethylene (LDPE) and other similar olefinic polymers. For example U.S. Patent No. 5,256,228 discloses a uniflable sheet material by heat for roof, prepared from a composition uncured polymer comprising 100 parts by weight of a mixture of polymer comprising 50 to 90 parts by weight of polyolefins with up to 2 percent by weight of crystallinity, from 10 to 50 parts by weight of a highly crystalline thermoplasticity promoter such as HDPE or LDPE; 50-250 parts by weight of a filling; and 20-150 parts by weight of a material of indicted.

Notwithstanding the presence of resins of Crystalline polyethylene have many disadvantages. For example higher levels of crystallinity result in lower stability dimensional thermal expansion or contraction over large temperature fluctuations observed in the change; This can result in breakage or fatigue of the sheet. In addition the Lower melting characteristics of polyethylene result in limitations for high temperature applications, such as in dark colored foil. Finally, polyethylene has a narrow range of melting point, resulting in a window of narrow heat welding process.

The polyolefin compositions that have Good mechanical properties have been used in many cases of application, due to the characteristics that are typical of polyolefins (such as chemical inertia, mechanical properties and not toxicity); In addition, these compositions show remarkable relationships of cost / benefit. In the state of the art these compositions are obtained by sequential copolymerization of propylene, optionally containing smaller amounts of comonomers olefinic, and then ethylene / propylene mixtures or ethylene / alpha-olefin. Catalysts based on halogenated titanium compounds supported on chloride Magnesium are commonly used for this purpose.

For example, U.S. Patent No. 5,286,564, on behalf of the petitioner, describes compositions of flexible polyolefins comprising, in part by weight:

A) 10-50 parts of a isotactic propylene homopolymer or copolymer;

B) 50-20 parts of a copolymer of ethylene, insoluble in xylene at room temperature; Y

C) 40-80 parts of a copolymer of ethylene / propylene containing less than 40% by weight of ethylene and being soluble in xylene at room temperature; viscosity intrinsic of said copolymer is preferably from 1.7 to 3 dl / g.

These compositions have module values flexural less than 150 MPa and Shore D hardness between 20 and 25. While these mechanical properties are advantageous for certain applications, the compositions prepared in the examples 1-5 show tensile strength values in breakage ranging from 13.8 to 17.3 MPa; for many applications, such as roofing sheets, these polymers do not show a satisfactory tenacity, which is a strictly property related to tensile strength at breakage and at elongation in breakage properties. Tenacity is fundamental in roofing applications, where there is a tendency to break of the roof under the action of the wind.

As is well known in art, resistance and the flexibility of thermoplastic polyolefin compositions  it can be improved by decreasing the rubber content; however at increased resistance is usually associated with an increase in rigidity which causes several inconveniences. For example, on the rise The stiffness of a flexible membrane limits the installation of the membrane around a corner, chimneys, vents, etc., in where the membrane must be flexible to bend around the obstruction.

European Patent No. 1202876.7, in the name of the applicant, describes a polyolefin composition that understands:

(TO)

Out of 8 at 25% by weight of a propylene homopolymer or copolymer crystalline, and

(B)

from 75 to 91% by weight of an elastomeric fraction comprising a first elastomeric propylene copolymer with 15-32% by weight of ethylene, intrinsic viscosity of the fraction soluble in xylene between 3.0 and 5.0 dl / g; Y a second elastomeric propylene copolymer with more than 32% up to 45% by weight of ethylene, oscillating the intrinsic viscosity of the fraction soluble in xylene between 4.0 and 6.5 dl / g.

These polyolefin compositions have flexural modulus values below 60 MPa and very good values hardness (Shore A hardness less than 90); nevertheless exhibit lower tenacity values. Indeed, the compositions of polyolefin prepared in examples 1-3 of the Patent cited above show tensile strength values at Break equal to 5.5, 11.7 and 11.2 MPa respectively. How has it exposed above these values are not entirely satisfactory for laminate ceilings, since increased flexibility is associated with improved rigidity

European patent EP 412 534 describes polyolefin compositions comprising (A) a homopolymer or propylene copolymer containing less than 5% by weight of soluble xylene matter, (B) a random copolymer of ethylene / propylene containing no more than 5% by weight of insoluble xylene, (C) in ethylene / propylene copolymer containing 15-40% by weight of propylene and (D) talc. These polyolefin compositions are suitable for use in the production of automobile bumpers.

U.S. Patent No. 5,360,868 describes several polyolefin compositions that have paintability enhanced to high flexural modulus, wherein said compositions comprise mixtures of a crystalline propylene homopolymer or propylene copolymer (A) and olefinic polymer composition (B) and optionally (C) a polymeric composition of propylene or (D) an olefinic polymer rubber.

There is therefore a strong need for softer materials that are easier to install and when at the same time possess a satisfactory tenacity, resistance, and resistance to breakage and puncture. In other words, it feels the need for polyolefin compositions that exhibit a good balance of flexibility over a variable temperature range, and tenacity, as well as good mechanical properties; Besides, you are compositions must be heat sealable and oil resistant and not they must suffer degradation when exposed to the elements.

The present invention relates to a composition polyolefin comprising:

(TO)

from about 15 to about 40% by weight of a copolymer propylene crystalline with at least one alpha-olefin of formula H 2 C = CHR 2 R 1, where R 1 is H or a linear or branched alkyl containing by at least about 90% by weight of propylene, and with solubility in xylene at room temperature below about 15% in weight;

(B)

from around 60 to about 85% by weight of a fraction elastomeric comprising:

(one)

a propylene copolymer with ethylene optionally containing about 0.5 to 5% by weight of a diene, containing about from 20 to about 35% by weight of ethylene and with solubility in xylene at room temperature exceeding about 70% by weight, the intrinsic viscosity of the fraction being soluble in xylene greater than about 3.0 dl / g to about 6.0 dl / g; Y

(2)

a ethylene copolymer with at least one alpha-olefin of formula H 2 C = CHR 2, wherein R 2 is a linear C 2-8 alkyl or branched, optionally containing about 0.5 to 5% by weight of a diene, containing about 15% to 40% by weight of alpha-olefin, with solubility in xylene at ambient temperature exceeding about 25% by weight, oscillating the intrinsic viscosity of the xylene soluble fraction between about 0.5 and about 5.0 dl / g;

the weight ratio (1) (2) ranges from around 1: 5 and around 5.1.

The present invention further relates to a procedure for the preparation of the polyolefin composition above, comprising at least three stages of sequential polymerization, conducting each polymerization subsequent in the presence of the polymeric material formed in the polymerization reaction immediately preceding, wherein the crystalline copolymer (A) is prepared in a first stage and the elastomeric fraction (B) is prepared in at least two stages subsequent. In accordance with a preferred embodiment all polymerization steps are carried out in the presence of a catalyst comprising a trialkylaluminum compound, optionally an electron donor and a catalytic component solid comprising a halide or halogen-alcoholate of Ti, and an electron donor compound supported on chloride of anhydrous magnesium, said solid catalyst component having a surface area (measured by BET) of less than about 200 m 2 / g, and a porosity (measured by BET) greater than about 0.2 ml / g.

The polyolefin compositions of the present invention show a significant improvement in strength and toughness,  without sacrificing rigidity; against the petitioner has found surprisingly that the rigidity of the compositions of the invention is reduced with respect to the compositions of the prior art that They contain lower amounts of rubber content. More specifically the compositions of the invention are provided with high toughness, as evidenced by resistance values breaking traction and breaking elongation much higher than thermoplastic resins of the prior art used in membranes of flexible roofing, while showing a noticeable reduction of stiffness

The compositions of the invention exhibit a very good balance of flexibility and mechanical properties, and in particular values of flexural modulus and Shore D hardness, while retaining good elastomeric properties. These soft compositions, easier to install even around corners and chimneys, show better consistency and resistance to tear as well as improved wind lift and puncture resistance; They are also equipped with good thermal weldability

The polyolefin compositions of the present invention comprise from about 15 to about 40% by weight, preferably from about 15 to about 35%, and even more preferably from about 20 to about 30%, of a crystalline propylene copolymer (A), and about 60 to about 85% by weight, preferably about 65 to around 85%, and even more preferably around 70 to about 80% by weight of an elastomeric fraction (B).

In the present description by "temperature environment "means approximately 25 ° C.

The crystalline copolymer (A) of the compositions of the invention is a propylene copolymer with a alpha-olefin H 2 C = CHR 1, wherein R 1 is H or a C 2-8 linear or branched alkyl, containing at least about 90% by weight of propylene, of Preference for at least about 95% propylene. This copolymer has solubility in xylene at room temperature less than about 15% by weight, preferably less than around 10%, and even more preferably less than around of 8%. Said alpha-olefin is preferably ethylene, 1-butene, 1-pentene, 4-methylpentene, 1-hexene, 1-octeno your combinations, and even more preferably it is ethylene.

The elastomeric fraction (B) of the polyolefin compositions of the invention comprise a copolymer of propylene with ethylene and an ethylene copolymer with a alpha-oelfin H 2 C = CHR 2, where R 2 is a linear or branched C 2-8 alkyl. By "elastomeric" is understood herein as a polymer that has low crystallinity or is amorphous, and with a solubility in xylene at ambient temperature exceeding about 40% by weight.

The copolymer (1) of propylene with ethylene contains from about 20 to about 35% by weight of ethylene, preferably from about 25 to about 30%, and has a Xylene solubility at room temperature greater than around 70% by weight, preferably greater than about 75%; the intrinsic viscosity of the xylene soluble fraction ranges from around 3.0 to about 6.0 dl / g, more preferably of around 3.5 to about 5.0 dl / g, and even more preferably from about 4.0 to about 4.5 dl / g.

The copolymer (2) is an ethylene copolymer with at least one alpha olefin of formula H 2 C = CHR 2, wherein R 2 is a linear or branched C 1-8 alkyl , optionally containing about 0.5 to 5% by weight of a diene; said alpha-olefin is preferably 1-butene, 1-hexene or 1-octene and even more preferably it is 1-butene. The alpha-olefin content ranges from about 15% to about 40% by weight, and preferably from about 20 to about 35%. The copolymer (2) has solubility in xylene at room temperature greater than about 25% by weight, preferably greater than about 30%, and the intrinsic viscosity of the xylene soluble fraction ranges from about 0.5 to about 5.0 dl / g, preferably between about 1.0 to about
43.5 dl / g.

As stated above the copolymers (1) and (2) of the elastomeric fraction (b) may contain  a diene, conjugated or not, such a butadiene dome, 1,4-hexadiene, 1,5-hexadiene and ethylidene-norbornene-1. The diene, when present, it is contained in an amount of about 0.5 to about 5% by weight, based on the weight of the fraction (B).

The weight ratio of the copolymers Elastomeric (1) / (2) ranges from about 1: 5 to about 5: 1, and preferably between about 1: 2 and about 2: 1.

The polyolefin composition of the invention, preferably prepared by sequential polymerization in At least three stages, it shows high tenacity, and in particular it has tensile strength at breakage ≥ 25 MPa (ASTM D 882, on a 100 µm film), more preferably ≥ 28 MPa; elongation at break ≥ 700 MPa (ASTM D 882, on a 100 µm film), more preferably ≥ 750 MPa, and toughness ≥ 150 MPa (ASTM D 638, on a 1 mm sheet), plus preferably ≥ 170 MPa.

In addition, said composition has a module flexural? 130 MPa, preferably? 100 MPa, and more preferably? 80 MPa; Shore hardness D ≤ 40 ° C, and of preference between about 25 to about 35; Y MFR <1.0 g / 10 min, preferably <0.8 g / 10 min, and even more preferably <0.6 g / 10 min.

In accordance with a preferred embodiment of invention the polyolefin composition takes the form of particles spherical having an average diameter of about 250 to around 7,000 microns, a fluidity of less than about 30 seconds and a mass density (compacted) greater than about 0.4 g / ml.

The polyolefin composition of the invention can be prepared by sequential polymerization in at least three stages; in accordance with a preferred embodiment, the sequential polymerization is carried out in the presence of a catalyst comprising a trialkylaluminum compound, optionally an electron donor, and a catalytic component solid comprising a halide or halogen-alcohoalt of Ti, and an electron donor compound supported on chloride of anhydrous magnesium.

The present invention is further directed a procedure for the preparation of the compositions polyolefins as indicated above, said said procedure at least three stages of polymerization sequentially conducting each subsequent polymerization in presence of the polymeric material formed in the reaction of immediately preceding polymerization, wherein the copolymer (A) it is prepared in at least a first stage, and the fraction Elastomeric (B) is prepared in at least two sequential stages. The polymerization steps can be carried out in the presence of a Zielger-Natta and / or metallocene catalyst.

Ziegler-Natta catalysts Appropriate are described in EP-A-45 977 and US 4,399,054; other examples can be found in US 4,472,524.

The solid catalytic components used in said catalysts they comprise, as electron donors (internal donors), compounds chosen from the group consisting of ethers, ketones, lactones, compounds containing atoms of N, P and / or S, and esters of mono- and dicarboxylic acids.

Electron donor compounds particularly suitable are esters of phthalic acid, such as diisobutyl, dioctyl, diphenyl and benzylbutyl phthalate.

Other appropriate electron donors are 1,3-diesters of the formula:

one

where R I and R II, same or different from each other, they are alkyl radicals C 1 -C 18, cycloalkyl C 3 -C 18 or aryl C 7 -C 18; R III and R IV, equal or different from each other, they are alkyl radicals C 1 -C 4; or are they 1,3-diesters where the carbon atom in position 2 belongs to a cyclic or polycyclic structure formed by 5, 6 or 7 carbon atoms and containing two to three unsaturations

Ethers of this type are described in EP-A-361 493 and EP-A-728 769.

Representative examples of said diesters are 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-Isopropyl-2-cyclopentyl-1,3-dimethoxy-propane, 2-isopropyl-2-isoamyl-1,3-dimethoxypropane, and 9,9-bis (methoxymethyl) fluorene.

The preparation of the catalytic components The aforementioned is carried out in accordance with various methods.

In accordance with a preferred method of preparation an adduct of MgCl2 is reacted (in particular in the form of spheroidal particles) where n is generally 1 to 3 and ROH is ethanol, butanol or isobutanol, with a excess of TiCl 4 containing the electron donor compound. The reaction temperature is generally between 80 and 120 ° C. The solid is then isolated and reacted once more. with TiCl 4 in the presence or absence of the donor compound of electrons, after which it separates and washes with parts aliquots of a hydrocarbon until all the disappeared chlorine ions

In the solid catalyst component the compound of titanium, expressed as Ti, is generally present in a amount from about 0.5 to about 10% by weight. The amount of electron donor compound that is fixed on the solid catalytic component is generally around 5 to 20% in moles with respect to magnesium dihalide.

The titanium compounds that can be used in the preparation of the solid catalyst component are halides and the halogen titanium alcoholates. The preferred compound is titanium tetrachloride

The reactions described above result in formation of a magnesium halide in active form. Other reactions  are known in the literature, which cause the halide formation of magnesium in active form from magnesium compounds different from halides, such as magnesium carboxylates.

Alkyl compounds used as co-catalysts comprise Al-trialkyls, such as Al-triethyl, Al-triisobutyl, Al-tri-n-butyl, and linear or cyclic Al-alkyl compounds containing two or more Al atoms linked together by means of O or N atoms, SO 4 O SO 3 groups. The compound Alkyl is generally used in an amount such that the Atl / Ti ratio is between about 1 and about 1000

The electron donor compounds that can be used as external donors include acid esters aromatics such as alkyl benzoates, and in particular compounds of silicon containing at least one Si-OR bond, where R is a hydrocarbon radical. Examples of compounds of silicon are (tert-butyl) 2 Si (OCH 3) 2,  (cyclohexyl) (methyl) Si (OCH 3) 2, (phenyl) 2 Si (OCH 3) 2 and (cyclopen-tyl) 2 Si (OCH 3) 2.  1,3-diesters having the formulas described before they can also be used advantageously. in case the internal donor is one of these diesters, the external donors

The solid catalyst component has, of preferably, a surface area (measured by BET) of less than about 200 m 2 / g and more preferably between around 80 and about 170 ml / g, and porosity (measured by BET) preferably greater than about 0.2 ml / g, and more preferably between about 0.25 and about 0.5 ml / g

The catalysts can be precontacted with small amounts of olefin (prepolymerization), maintaining the suspension catalyst in a hydrocarbon solvent, and polymerizing at room temperature between 60 ° C, producing thus a quantity of polymer between about 0.5 and about 3 times the weight of the catalyst. The operation can take place also liquid monomer, producing, in this case, an amount of polymer 1000 times the weight of the catalyst.

With the use of the aforementioned catalysts, the polyolefin compositions are obtained in the form of spheroidal particles, the particles having an average diameter between about 250 and about 7,000 microns, a fluidity of less than about 30 seconds and a mass density (compacted ) greater than about
0.4 g / ml.

Other catalysts that can be used in the procedure according to the present invention are metallocene type catalysts, as described in EP-A-0 129 368 and US 5,324,800; particularly advantageous are metallocenes of bridged bis-indenyl, for example as described in EP-A-0 485 823 and US 5,145,819. Another class of appropriate catalysts are the so-called constrained geometry catalysts, as described in EP-A-0 416 815, EP-A-0 420 436, EP-A-0 671 404, EP-A-0 643 066 and WO 91/04257. These Metallocene compounds can be used to produce copolymers (1) and (2) of the elastomeric fraction (B).

In accordance with a preferred embodiment the The polymerization process of the invention comprises three stages, all carried out in the presence of catalysts of Ziegler-Natta, where: in the first stage the relevant monomer (s) are polymerize to form the crystalline copolymer (A); in the second stage a mixture of propylene and ethylene is polymerized, and optionally a diene to form the copolymer (B) (1); and in the third stage a mixture of ethylene and a alpha-olefin H 2 C = CH 2, and optionally a diene, polymerize to form copolymer (B) (2).

The polymerization steps can occur in the liquid phase, in the gas phase or in the liquid-gas Preferably the polymerization of the crystalline copolymer fraction (A) is carried out in monomer liquid (for example using liquid propylene as diluent), while the copolymerization stages of the copolymers (B) (1) and (B) (2) are carried out in the gas phase, without stages intermediate except for partial degassing of propylene. In accordance with a more preferred embodiment all stages of Sequential polymerization are carried out in the gas phase.

The reaction temperature in the stage of polymerization for the preparation of the crystalline copolymer (A) and in the preparation of the copolymers (B) (1) and (B) (2) can be same or different and is preferably around 40 ° C at around 90 ° C; more preferably the reaction temperature ranges between about 50 and about 80 ° C in the preparation of fraction (A), and from about 40 to about 80 ° C to the preparation of components (B) (1) and (B) (2).

The polymerization stage pressure for prepare fraction (A), if carried out in liquid monomer, it is the one that corresponds to the vapor pressure of the liquid propylene at the operating temperature used, and possibly modified by the vapor pressure of the small amount of diluent inert used to feed the catalytic mixture, and the overpressure of monomers and optionally used hydrogen  as a molecular weight regulator.

The polymerization pressure ranges from preference, between about 33 and about 43 bar, in case to be performed in liquid phase, and from about 5 to about 30 bar to be carried out in the gas phase. The residence times of the three stages depend on the desired relationship between the fractions and They can range between about 15 minutes and 8 hours. They can known conventional molecular weight regulators be used in art, such as chain transfer agents (for example hydrogen or ZnEt2).

The compositions of the invention can be used in combination with other elastomeric polymers, such as ethylene / propylene copolymers (EPR), terpolymer of ethylene / propylene / diene, ethylene copolymer with C4-C2 alpha-olefins (per example ethylene / octene-1 copolymers, such as those sold under the name Engage®) and their mixtures. These Elastomeric polymers can be present in an amount of 5 at 80% by weight over the total composition.

In addition to these polymeric components the Composition of the present invention can be mixed with additives common, such as reinforcing and non-reinforcing fillers, pigments, nucleating agents, extension oils, mineral fillers, flame retardants (for example aluminum trihydrate), antioxidants, UV resistant (for example titanium dioxide), UV stabilizers, lubricants (for example oleamide (agents anti-blocking, antistatic agents, waxes, coupling agents for fillers and other processing means known in the art of polymer formation. Pigments and other additives can comprise up to about 50% by weight of the total composition based on the most additive polymer components; from preference pigments and fillers comprise above about from 0 to about 30 percent by weight of the total composition.

In view of the properties described above, polyolefin compositions of the present invention are valuable in Roofing membrane production to cover flat roofs industrial and commercial, and in other roofing applications. In effect, they have a high tenacity, while retaining softness and Good mechanical properties

In addition, roofing membranes obtained with the polyolefin compositions of the invention are waterproof, economical manufacturing and durable, with a fairly long half-life superior to current commercial roof coverings that are obtained using glass fibers or asphalt.

Roofing membranes formed from the polyolefin compositions of the present invention can occur with any method conventionally used to produce roofing membranes from polymer compositions filled. For example, membranes can be formed by conventional grinding, calendering or extrusion techniques. Other methods, including spray coating and Roll die formation can be used. In accordance with a preferred embodiment, the polymer compositions of the invention are laminated to thicknesses ranging from about 5 and about 200 mils. Lamination can be cut to length desired and wide dimensions at this time.

Roofing membranes formed from the compositions of the present invention may optionally Reinforce with cotton or linen fabric. In addition to the membranes of roofing the polyolefin compositions of this invention can be used to produce underlying materials, used as roofing felt substituents.

Roofing membranes can be applied in same way and circumstances as asphalt or fiber membranes Conventional glass These have light weight, providing potential cost savings in the design of roof supports structural, as well as an ease of application. These provide relevant strength and durability, along with excellent temperature stability, impermeability and resilience

A method of covering a roof comprises the steps of applying sheets of the polymeric material of the invention to the roof to be covered; overlapping adjacent edges of the layers by heating the overlapping areas slightly above softening point of the sheet material and joining the areas overlapping using enough heat and pressure to provide an acceptable bond strength. Polymeric compositions They have sufficient self-adhesion without the use of an adhesive.

The analytical methods that follow have been used to determine the properties exposed in the Detailed description and in the examples.

\ underline {Property}

\ underline {Method}

Melt Flow Rate (MFRL)

ASTM D 1238 condition L 230 ° C, 2.16 kg)

Ethylene% by weight

I.R. Spectroscopy

1-butene% in weigh

I.R. Spectroscopy

Viscosity intrinsic

In tetrahydronaphthalene, to 135 ° C

Shore D hardness

ASTM D 2240

Flexural module a 23ºC

ASTM D730M (after 3 h)

Traction module

ASTM D 882 on 100 cast film um, with a speed of 5 mm / min

2% secant module

ASTM D 638; on 1 mm, 25.4 mm extruded sheet x 152.4 mm (1``x6 '') cutting die, without extensometer; test speed of 25.4 mm / min (1 '' / min); Temperature of 23ºC, -40ºC and 85ºC test. This test characterizes the stiffness of the material.

Tensile strength in breakage and transfer

1) ASTM D 882, after 3 hours, on 100 µm casting film, 50mm / min test speed

quad

2) ASTM D 638, test speed of 50 mm / min on 1 mm extruded sheet, at 23 ° C. Type IV die cut, without  extensometer For tests at -40 ° C, an environmental chamber was used and samples Type S D1822.

Elongation at break and with assignment

1) ASTM D 882, after 3 hours, on 100 µm cast film, test speed of 50 mm / min

quad

2) ASTM D628 on 1 mm extruded sheet. cut Type IV matrix, without extensometer. For tests at -40 ° C, used an environmental camera and samples Type S D1822.

Tenacity

ASTM D 638, on 1 mm extruded sheet; Test temperatures of 23ºC and -40ºC. Tenacity defined as the area under stress-elongation curve.

Resistance to break

ASTM D 1004; test speed 50 mm / min; test temperatures of 23 ° C; a sample was used V-shaped die cut.

Longitudinal CLTE

ASTM E831-86; before measurement the sample is conditioned in the TMA apparatus (thermodynamic analysis) at 120 ° C for 10 minutes in order to erase the effort Induced in the sample (2.5 mm thick and 10 mm long) by injection molding. The dilation is then measured in a temperature range from 0 to 45 ° C, at scanning speed of 3ºC / min under a flat probe (diameter of 3.66 mm) with a load of 1 mN

Superficial area

B.E.T.

Porosity

B.E.T.

Bulk density

DIN 53194

Determination of solubility in xylene at room temperature (% in weigh)

2.5 g of polymer was dissolved in 250 ml of xylene, at 135 ° C, under stirring. After 20 minutes the solution up to 25 ° C under stirring and then allowed to settle for 30 minutes

The precipitate was filtered with filter paper; be evaporated the solution under a stream of nitrogen and dried the residue under vacuum at 80 ° C until constant weight is reached. Then I know calculated the weight percentage of the xylene soluble polymer at room temperature. The percentage by weight of polymer insoluble in Xylene at room temperature was considered the isotactic index of polymer. This value corresponded substantially to the index isotactic determined by extraction with boiling n-heptane, which by definition constitutes the isotactic index of polypropylene.

Unless otherwise indicated samples that have to undergo the various analyzes physico-mechanics were molded with the use of a injection press Negri & Bossi 90, after stabilizing the sample with hindered phenolic stabilizer IRGANOX R 1010 (0.05% by weight), and phosphite stabilizer IRGAFOS 168 (0.1% by weight), and pelletize the sample with a double screw Berstorff extruder (cylinder diameter 25 mm) at 210 ° C.

The conditions were as follows:

- melting temperature: 220 ° C;

- mold temperature: 60 ° C;

- injection time: 9 sec ..;

- cooling time: 15 sec.

The dimensions of the plates for testing they were 127x127x2.5 mm. From these plates were cut Type C weights and underwent tensile strength tests with a head speed of 500 mm / min. They were also cut from These plates samples for the flexural module and Shore D hardness. All samples were cut parallel to the feed front and by consequently perpendicular to the flow direction.

Examples 1 and 2

Catalytic System Preparation

A catalytic component consisting of MgCl 2 • 3 H 2 OH was prepared as follows:

28.4 g of anhydrous MgCl2 was introduced, 49.5 g of pure anhydrous ethanol, 100 ml of petroleum jelly ROL OB / 30, and 100 ml of silicone oil (viscosity 3250 cs) in a flask immersed in a thermoregulated bath, at 120 ° C under stirring, in an inert atmosphere, until the MgCl2 was dissolved by full. Then the hot mixture was transferred, always under a inert atmosphere, in a 150 ml container equipped with a heating jacket, and containing 150 ml of petroleum jelly and 150 ml of silicone oil. The mixture was kept at 120 ° C and under agitation, taking place with a shaker Hanke & Kunkel K.G. Ika Werke Ultra Turrax T-45 N. Se stirring continued for 3 minutes at 3000 rpm. The download was downloaded mixture in a 2 liter container containing 1000 ml of anhydrous n-heptane stirred and cooled so that the final temperature did not exceed 0 ° C. The microspheres of MgCl 2 • 3 Ethanol thus obtained were filtered and dried under vacuum at room temperature. The dried adduct obtained in this way it was then desalcoholó by heating at temperatures gradually increasing from 50ºC to 100ºC, under a current of nitrogen, until the alcohol content was 1.1 moles per mol of MgCl2.

The partially chipped adduct thus obtained had a surface area of 11.5 m2 / g, a porosity 0.13 ml / g and mass density of 0.564 g / ml.

25 g of the adduct obtained were added, under stirring at 0 ° C, 625 ml of TiCl 4. Then the mixture was heated at 100 ° C in 1 hour. When the temperature reached 40 ° C it was added diisobutylphthalate in an amount such that the molar ratio Mg / diisobutylphthalate was 8. The resulting mixture was heated to 100 ° C for 2 more hours, then allowed to settle and separated by Siphoning the liquid. 500 ml of TiCl4 was added and heated the mixture at 120 ° C for 1 hour.

The obtained mixture was allowed to settle and siphoned the liquid. The solid was washed 6 times using 200 ml of anhydrous hexane at 60 ° C and three more times using 200 ml of anhydrous hexane at room temperature.

After drying under vacuum the solid presented porosity equal to 0.383 ml / g and surface area equal to 150 m2 / g.

General Polymerization Procedure

The polymerizations were carried out in reactors of fluidized bed of stainless steel.

During the polymerization the gas phase in Each reactor was continuously analyzed by gas chromatography in order to determine the content of ethylene, propylene and hydrogen. Ethylene, propylene, 1-butene was fed and hydrogen so that during the course of the polymerization its gas phase concentration was kept constant, using instruments that measure and / or regulate the flow of monomers

The operation was continuous in three stages, each one comprising the polymerization of the phase monomers soda.

Propylene was prepolymerized in liquid propane in an 80 liter stainless steel closed circuit reactor with an internal temperature of 20 ° C, for a period of 30 minutes, with a propylene feed of 30 kg / h, in the presence of a catalytic system comprising a solid component (26 g / h) prepared as described before, and a mixture of 75-80 g / h of Altriethyl (TEAL) in a solution of 10% hexane and an appropriate donor amount of dicyclopentyldimethoxysilane (DCPMS), so that the ratio TEAL / DCPMS weight was 5. The catalyst was prepared from Compliance with the procedure outlined above.

First stage

The prepolymer thus obtained in the first gas phase reactor, with a temperature of 60 ° C and a 14 barg pressure Then hydrogen, propylene, ethylene was fed and an inert gas in the ratio and quantities shown in the Table 1, to obtain the composition of the gas phase exposed in the Table 1, and polymerization was carried out over time set out in Table 1.

Second stage

After separating a sample to carry after the various analyzes the polymer obtained from the first stage in the second phase reactor with a temperature of 60 ° C and a pressure of 18 barg. Then hydrogen was fed, propylene, ethylene and an inert gas in the ratio and quantities set out in Table 1, to obtain the phase composition gas shown in Table 1, and polymerization was carried out during the time shown in Table 1.

Third stage

After separating a sample to carry after the various analyzes the polymer obtained from the first stage in the second phase reactor with a temperature of 75 ° C and a pressure of 14 barg. Then hydrogen was fed, ethylene, 1-butene and an inert gas in the ratio and amounts shown in Table 1, to obtain the composition of the gas phase set forth in Table 1, and the polymerization during the time set forth in Table 1.

At the end of the polymerization, the particulate polymer, at atmospheric pressure, in a container in where a countercurrent steam was fed in order to dissociate the remaining monomers. Then the polymer was discharged in a vessel, where nitrogen was fed countercurrent to 80-90 ° C in order to dry the polymer.

The operating conditions used in the previous procedure and the results of the analyzes led to conducted on the polymer compositions obtained are shown in Tables 1 and 2, respectively.

Examples 3-5

The polymerization procedure was repeated from example 1, with the exception that the conditions were used  following in the polymerization stages:

-

in the Stage 1, the polymerization was carried out at a temperature of 60 ° C and under a pressure of 14 barg, during the time exposed in the Table 1;

-

in the Stage 2, the polymerization was carried out at a temperature of 60 ° C and under a pressure of 18 barg, during the time exposed in the Table 1;

-

in the Step 3, the polymerization was carried out at a temperature of 77 ° C and under a pressure of 14 barg, during the time exposed in the Table 1.

The operating conditions used in the previous procedure and the results of the analyzes led to conducted on the polymer compositions obtained are shown in Tables 1 and 2, respectively.

Examples 6 and 7

The polymerization procedure was repeated from example 1, with the exception that the conditions were used  following in the polymerization stages:

-

in the Stage 1, the polymerization was carried out at a temperature of 60 ° C and under a pressure of 14 barg, during the time exposed in the Table 1;

-

in the Stage 2, the polymerization was carried out at a temperature of 60 ° C and under a pressure of 18 barg, during the time exposed in the Table 1;

-

in the Step 3, the polymerization was carried out at a temperature of 80 ° C and under a pressure of 14 barg, during the time exposed in the Table 1.

The operating conditions used in the previous procedure and the results of the analyzes led to conducted on the polymer compositions obtained are shown in Tables 1 and 2, respectively.

TABLE 1

Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex. 6 Ex.7 1st phase (gas phase) Breaking (% in weight) 25 26 twenty-one twenty 26 22 18 Weather (minutes) 60 80 93 92 128 140 150 H2 in the gas phase (% mol) 1.10 1.23 0.09 0.08 0.09 0.02 0.02 Gas phase ethylene (% mol) 0.3 0.2 0.2 0.2 0.2 0.2 0.2 Propylene in the gas phase (% mol) 8.6 8.7 7.4 9.0 8.6 9.0 8.9 Ethylene in (A) (% in p) 3.4 3.0 3.4 3.5 3.4 3.2 3.1 MFR "L" (g / 10 min) 38.4 38.4 47.7 7.4 6.3 2.8 2.9 Sun. Xyl. (% in weight) 7.9 8.1 7.0 7.0 7.0 7.3 7.3 2nd phase (gas phase) Breaking (% in weight) 35 41 39 37 35 22 36 Weather (minutes) 25 2. 3 twenty twenty 2. 3 16 16 H2 in the gas phase (% mol) 0.32 0.34 0.32 0.29 0.31 0.31 0.30 Gas phase ethylene (% mol) 11.0 11.7 10.3 10.7 10.7 11.2 11.6 Propylene in the gas phase (% mol) 58.1 55.8 53.6 56.9 57.1 55.8 55.7 Ethylene in (B) (1) (% in p) 30 30 27 28 28 28 29 Ethylene tot. (% In p.) 18.9 19.3 18.9 19.3 17.6 17.9 19.9 MFR "L" tot. (G / 10 min) 0.34 0.42 0.22 0.19 0.28 0.24 0.20 Sol.Xil.tot.in (B) (1) (% in weight) 91 90 91 91 91 91 90 Sol.Xil.tot. (% In p.) 55.7 57.9 61.6 62.0 55.0 56.0 62.1 I.V. Sun. Xil. (dl / g) 4.1 4.3 4.1 4.5 4.1 4.1 4.2 3rd phase (gas phase) Breaking (% in weight) 40 33 40 43 39 46 46 Weather (minutes) 110 100 77 90 115 130 125 H2 in the gas phase (% mol) 3.30 3.02 8.89 5.34 7.52 8.90 8.66 Gas phase ethylene (% mol) 38.6 36.2 42.7 41.9 43.2 43.9 43.2 1-butene gas phase (% mol) 26.1 24.8 27.4 27.6 27.7 27.6 26.1 1-butene in (B) (2) (% in weight) twenty twenty-one 22 21.5 twenty-one twenty-one twenty-one Sol.Xil.in (B) (2) (% in weight) 37 35 39 37 40 37 35 I.V. Sol. Xyl. (B) (2) (dl / g) 4.2 * 1.8 * 1.5 * 2.1 * 1.6 * 1.1 * 1.00 *

TABLE 2

Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex. 6 Ex.7 MFR "L" (g / 10 min) 0.23 0.26 0.42 0.33 0.32 0.6 0.4 Sol.Xil. (% in weight) 48.1 50.0 56.4 51.1 51.0 47.4 49.5 Ethylene content (% in weight) 43.1 39.1 43.2 45.4 41.0 46.0 47.0 1-Butene content (% in weight) 7.8 7.4 9.2 8.7 8.5 10.0 9.9 I.V. Sol.Xil. (Dl / g) 4.16 3.67 3.31 3.76 3.34 3.06 3.18 Flexural module (MPa) 84 93 52 59 68 60 59 Traction module (MPa) 75 63 51 63 81 74 60 Tensile strength with breakage (1) (MPa) 26.6 34.5 29.8 34.0 37.0 31.8 29.9 Elongation at break (1) (%) 795 880 746 731 841 831 819 Shore D hardness (ºS) 35.8 35.0 30.2 32.4 33.4 31.0 31.6 Longitudinal CLTE (ºC -1 x10-5) 12.5 14.3 9.8 10.6 7.6 7.2 8.1

Examples 1 and 2 comparatives

For comparative purposes, polyolefin compositions comprising a propylene / ethylene copolymer were tested.
Crystalline leno (A) and an elastomeric propylene / ethylene copolymer (B), in accordance with the procedures indicated above. The characteristics of these compositions, obtained as reactor grades, are shown in Table 3.

TABLE 3

Ex. 1 comp. Ex. 2 comp. propylene / ethylene copolymer (A) (% in weight) 31 33 Ethylene in (A) (% by weight) 3.2 3.8 Sol. Xill. (A) (% by weight) 6.0 5.5 cop. of propylene / ethylene (B) (% in weight) 69 67 Ethylene in (B) (% by weight) 27 28 Ethylene content (% in weight) 19.6 20.0 Sol.Xil.tot. (% By weight) 64.0 62.5 I.V. Sol.Xil. (Dl / g) 3.2 3.2 MFR "L" (g / 10 min) 0.6 0.45 Module flexural (MPa) 80 89 Traction Module (MPa) 52 55 Tensile strength with breakage (1) (MPa) 23.9 24.0 Elongation at break (%)(one) 740 700 Hardness Shore D (ºS) 32.6 33.0

The previous results show that Compositions of the present invention show very good values of flexibility, associated with an increase in toughness (resistance to traction with breakage and elongation with breakage).

Roofing application tests

The characterizations that follow, specific for roofing applications, they were carried out on the compositions obtained in the examples indicated above.

Sample preparation and characterization

On an extruder of a screw Killion of 1.25 '' single screw, with a set cylinder temperature at 230 ° C, the polymer composition tested relative to to melt processing using phosphite (Irgafos 168), phenol sterically hindered (Irganox 1010), and calcium stearate as acid collector The composite composition was then extruded to form a sheet 1 mm x 200 mm wide on an extruder of 1.5 '' single screw Killion blades. Sheet samples were cut with matrix to obtain traction samples ASTM D 638 type IV Tensile properties were measured using a Instron tensile tester with a crosshead speed of 500 mm / min

The results of the previous measurements are set forth in Table 4 below:

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TABLE 4

Property Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex. 6 Ex.7 Ex.2 comp. Temp. test 23 ° C Resistance to traction with break 26.8 24.3 20.6 24.3 25.1 21.7 22.3 18.3 (2) (MPa) Elongation with breakage (2)(%) 1480 1495 1485 1500 1585 1500 1520 1445 Elongation with assignment (2)(%) 24 25 25 28 26 24 26 22 Tenacity (MPa) 198 191 158 182 201 168 174 144 Breaking strength (N / mm) 72 70 63 68 70 67 63 63 2% drying module (MPa) 71 77 58 65 71 66 61 78 Temperature of test -40 ° C Tensile strength with break 33 27 2. 3 27 24 25 24 24 (2) (MPa) Elongation with breakage (2) (MPa) 678 573 541 550 593 599 614 271 Tenacity (MPa) 149 128 102 121 117 122 47 2% drying module (MPa) 540 462 442 425 456 372 513 464

The previous results show an improvement of flexibility of the compositions of the invention, with an increase corresponding in tensile strength, toughness and tear with respect to the polyolefin compositions known in the state of the art

Hot air weldability test

Hot air weldability is a test Specific for single layer roofing applications. The welds were formed by overlapping 25.4 mm wide areas of the net sheet Hot air was blown at the interface of the two sheets at a controlled temperature. The speed or time of heating was controlled, as well as the joint pressure in the interface. The test was carried out on extruded sheets of 1 mm, using a Leister precision hot air welder X84 The welding temperatures tested were 275ºC, 345ºC and 415 ° C, at a welding speed of 1.3 m / min, for Provide a weld window evaluation.

The detachment test was carried out on hot air welding at 23 ° C using strips of 25 mm die cut, measuring the shear force and lengthening with the fault. The failure mode was determined by visual examination of the sample that fails. Table 5 provides the Results of previous tests.

TABLE 5

Property Example 1 Example 3 Temp. of air hot 275 ° C Force of detachment (N) 173 178 Elongation (%) 749 1203 Failure mode Breakage of sheet Film breakage Temp. hot air 345 ° C Detachment force (N) 151 182 Elongation (%) 980 1655 Failure mode Breakage of sheet Film breakage Temp. hot air 345 ° C Detachment force (N) 187 173 Elongation (%) 877 1106 Failure mode Breakage of sheet Film breakage

Other features, advantages and achievements of the invention described herein will be readily apparent to the art expert after reading the description that precedes. In this regard, although embodiments have been described specific to the invention in considerable detail can be made variations and modifications of these embodiments without departing of the spirit and scope of the invention as described and vindicate

Claims (13)

1. A polylefin composition that understands

(TO)

from 15 to 40% by weight of a crystalline propylene copolymer with at least one alpha-olefin of formula H 2 C = CHR 2 R 1, where R 1 is H or a linear alkyl or branched containing at least 90% by weight of propylene, and with solubility in xylene at room temperature below 15% in weight;

(B)

from 60 to 85% by weight of an elastomeric fraction that understands:

(one)

a propylene copolymer with ethylene optionally containing 0.5 at 5% by weight of a diene, containing from 20 to 35% by weight of ethylene and with solubility in xylene at room temperature above 70% by weight, the intrinsic viscosity (in tetrahydronaphthalene being, at 135 ° C) of the fraction soluble in xylene greater than 3.0 dl / g up to 6.0 dl / g; Y

(2)

a ethylene copolymer with at least one alpha-olefin of formula H 2 C = CHR 2, wherein R 2 is a linear C 2-8 alkyl or branched, optionally containing 0.5 to 5% by weight of a diene, containing 15% to 40% by weight of alpha-olefin, with solubility in xylene at ambient temperature exceeding 25% by weight, oscillating it intrinsic viscosity (in tetrahydronaphthalene, at 135 ° C) of the xylene soluble fraction between 0.5 and 5.0 dl / g;

oscillating the weight ratio (1) (2) between 1: 5 and 5.1. 2. The polyolefin conformity composition with claim 1, wherein the amount of the copolymer Crystalline (A) ranges from 15 to 35% by weight. 3. The polyolefin conformity composition with claim 1, wherein the crystalline copolymer (A) It contains at least 95% by weight of propylene and has solubility in xylene at room temperature below 10% by weight. 4. The polyolefin conformity composition with claim 1, wherein in the crystalline copolymer (A) said alpha-olefin is ethylene. 5. The polyolefin conformity composition with claim 1, wherein the copolymer (1) of the fraction (B) contains 25 to 30% by weight of ethylene and has solubility in xylene at room temperature greater than 75% by weight, oscillating the intrinsic viscosity (in tetrahydronaphthalene at 135 ° C) of the Xylene soluble fraction between 3.5 and 5.0 dl / g. 6. The polyolefin conformance composition with claim 1, wherein the copolymer (2) of the fraction (B) contains 20 to 35% by weight of alpha olefin and has solubility in xylene at room temperature greater than 30% by weight, oscillating the intrinsic viscosity (in tetrahydronaphthalene, at 135 ° C) of the Xylene soluble fraction of 1.0 to 4.5 dl / g. 7. The polyolefin conformity composition with claim 1, wherein in the copolymer (2) of the fraction (B), said alpha-olefin is 1-butene, 1-hexene or 1-octene. 8. The polyolefin conformity composition with claim 1, which has tensile strength with breakage ≥ 25 MPa (ASTM D 882, on a 100 µm film), elongation with breakage ≥ 700 MPa (ASTM D 882, on a 100 µm film), and toughness ≥150 MPa (ASTM D 638, on a 1 mm sheet). 9. The polyolefin conformity composition with claim 7, which has tensile strength with breakage ≥28 MPa (ASTM D 882, on a 100 µm film), elongation with breakage ≥ 750 MPa (ASTM D 882, on a 100 µm film), and toughness ≥170 MPa (ASTM D 638, on a 1 mm sheet). 10. A procedure for the preparation of a polyolefin composition according to claim 1, comprising at least three polymerization stages sequentially conducting each subsequent polymerization in presence of the polymeric material formed in the reaction of immediately preceding polymerization, wherein the copolymer crystalline (A) is prepared in at least a first stage, and the elastomeric polymer fraction (B) is prepared in at least two sequential stages, carrying out all the stages of polymerization in the presence of a catalyst comprising a trialkylaluminum compound, optionally a donor of electrons, and a solid catalytic component comprising a Ti halide or halogen-alcoholate and a compound electron donor supported on anhydrous magnesium chloride, said solid catalyst component having a surface area (measured by BET) of less than 200 m2 / g and a porosity (measured by BET) greater than 0.2 ml / g. 11. The procedure, in accordance with the claim 10, wherein the polymerization steps Sequential ones are carried out all in the gas phase. 12. Sheets that comprise the composition polyolefin of claim 1. 13. Simple roofing sheet comprising the polyolefin composition of claim 1.